Re: [fuse-devel] [PATCH v3 2/2] FUSE: Adapt readdirplus to application usage patterns

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Miklos,

Are you using the "for-next" branch of the following tree?

http://git.kernel.org/?p=linux/kernel/git/mszeredi/fuse.git;a=summary

I didn't see the first part applied. If not, I could rebase to that
branch and send a patch set with the second part split out as a
separated patch.

On Fri, Jan 25, 2013 at 10:16 PM, Miklos Szeredi <mi...@sz...> wrote:
> On Tue, Jan 15, 2013 at 4:23 AM, Feng Shuo <ste...@gm...> wrote:
>> Use the same adaptive readdirplus mechanism as NFS:
>>
>> http://permalink.gmane.org/gmane.linux.nfs/49299
>
> OK, applied with minor updates.
>
>> If the user space implementation wants to disable readdirplus
>> temporarily, it could just return ENOTSUPP. Then kernel will
>> recall it with readdir.
>
> I removed this part.  It may make sense, but it's not part of the
> adaptive readdirplus algorithm, so I'd like to see this as a separate
> patch.
>
> Thanks,
> Miklos
>
>
>
>> Signed-off-by: Feng Shuo <ste...@gm...>
>> ---
>>  fs/fuse/dir.c    | 50 ++++++++++++++++++++++++++++++++++++++++++++++----
>>  fs/fuse/fuse_i.h | 10 ++++++++++
>>  fs/fuse/inode.c  |  3 +++
>>  3 files changed, 59 insertions(+), 4 deletions(-)
>>
>> diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
>> index dcc1e52..b9975df 100644
>> --- a/fs/fuse/dir.c
>> +++ b/fs/fuse/dir.c
>> @@ -14,6 +14,34 @@
>>  #include <linux/namei.h>
>>  #include <linux/slab.h>
>>
>> +static bool fuse_use_readdirplus(struct inode *dir, struct file *filp)
>> +{
>> +       struct fuse_conn *fc = get_fuse_conn(dir);
>> +       struct fuse_inode *fi = get_fuse_inode(dir);
>> +
>> +       if (!fc->do_readdirplus)
>> +               return false;
>> +       if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state))
>> +               return true;
>> +       if (filp->f_pos == 0)
>> +               return true;
>> +       return false;
>> +}
>> +
>> +static void fuse_advise_use_readdirplus(struct inode *dir)
>> +{
>> +       struct fuse_inode *fi = get_fuse_inode(dir);
>> +
>> +       set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state);
>> +}
>> +
>> +static void fuse_stop_use_readdirplus(struct inode *dir)
>> +{
>> +       struct fuse_inode *fi = get_fuse_inode(dir);
>> +
>> +       clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state);
>> +}
>> +
>>  #if BITS_PER_LONG >= 64
>>  static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
>>  {
>> @@ -219,6 +247,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
>>                                        attr_version);
>>                 fuse_change_entry_timeout(entry, &outarg);
>>         }
>> +       fuse_advise_use_readdirplus(inode);
>>         return 1;
>>  }
>>
>> @@ -355,6 +384,7 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
>>         else
>>                 fuse_invalidate_entry_cache(entry);
>>
>> +       fuse_advise_use_readdirplus(dir);
>>         return newent;
>>
>>   out_iput:
>> @@ -1294,7 +1324,7 @@ static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file,
>>
>>  static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
>>  {
>> -       int err;
>> +       int plus, err;
>>         size_t nbytes;
>>         struct page *page;
>>         struct inode *inode = file->f_path.dentry->d_inode;
>> @@ -1314,10 +1344,13 @@ static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
>>                 fuse_put_request(fc, req);
>>                 return -ENOMEM;
>>         }
>> +
>> +       plus = fuse_use_readdirplus(inode, file);
>> +read_again:
>>         req->out.argpages = 1;
>>         req->num_pages = 1;
>>         req->pages[0] = page;
>> -       if (fc->do_readdirplus) {
>> +       if (plus) {
>>                 attr_version = fuse_get_attr_version(fc);
>>                 fuse_read_fill(req, file, file->f_pos, PAGE_SIZE,
>>                                FUSE_READDIRPLUS);
>> @@ -1329,8 +1362,17 @@ static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
>>         nbytes = req->out.args[0].size;
>>         err = req->out.h.error;
>>         fuse_put_request(fc, req);
>> +       if ((err == -ENOTSUPP) && plus) {
>> +               fuse_stop_use_readdirplus(inode);
>> +               plus = 0;
>> +               req = fuse_get_req(fc);
>> +               if (!IS_ERR(req))
>> +                       goto read_again;
>> +               err = PTR_ERR(req);
>> +               goto out;
>> +       }
>>         if (!err) {
>> -               if (fc->do_readdirplus) {
>> +               if (plus) {
>>                         err = parse_dirplusfile(page_address(page), nbytes,
>>                                                 file, dstbuf, filldir,
>>                                                 attr_version);
>> @@ -1339,7 +1381,7 @@ static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
>>                                             dstbuf, filldir);
>>                 }
>>         }
>> -
>> +out:
>>         __free_page(page);
>>         fuse_invalidate_attr(inode); /* atime changed */
>>         return err;
>> diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
>> index 5c50553..e582603 100644
>> --- a/fs/fuse/fuse_i.h
>> +++ b/fs/fuse/fuse_i.h
>> @@ -103,6 +103,16 @@ struct fuse_inode {
>>
>>         /** List of writepage requestst (pending or sent) */
>>         struct list_head writepages;
>> +
>> +       /** Miscellaneous bits describing inode state */
>> +       unsigned long state;
>> +};
>> +
>> +/** FUSE inode state bits */
>> +enum {
>> +       /** Advise readdirplus  */
>> +       FUSE_I_ADVISE_RDPLUS,
>> +       /* FUSE_I_MTIME_UPDATED, */
>>  };
>>
>>  struct fuse_conn;
>> diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
>> index 6f7d574..4ba1cf5 100644
>> --- a/fs/fuse/inode.c
>> +++ b/fs/fuse/inode.c
>> @@ -255,6 +255,9 @@ static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
>>                                    new_decode_dev(attr->rdev));
>>         } else
>>                 BUG();
>> +
>> +       /* The readdir_plus is disabled initially. */
>> +       get_fuse_inode(inode)->state = 0;
>>  }
>>
>>  int fuse_inode_eq(struct inode *inode, void *_nodeidp)
>> --
>> 1.7.12.4
>>
>>
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-- 
Feng Shuo
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